I'm prepping a head and turbo to swap into my 93 940T. Head is a 530.
I'm doing minor port touch-ups re: stealthfti's site, lips here and there, using touch to try to get them all the same. I ground down the intake guides also. You don't need those, right?

In looking at the head and at many pics of heads, and some discussion of cooling passages, and that some have said that no.3 cyl runs lean/hot, I was thinking about the holes in the block and hg that do not have matching holes in the head. IOW, the GrpA mod.

I note that the cyls have different coolant passages near them.
No1 has two, 180 apart.
No2 and 3 have two, towards the intake valve
No4 has 3, two at the intake end, one at the exh end.
Hmm; I thought I knew where the pics were of the GrpA mod were, with 6mm and 4mm holes drilled along the cyls and at the back of the head; now I can't find them. Well anyway, I was thinking this was probably a good idea, esp at cyl3.
Comments? And links to pics?

__________________

Quote:

Originally Posted by Ursan

What's the female equivalent to a dick pic? twat shot?

Quote:

Originally Posted by XxJenoxX

There isn't one because dudes aren't grossed out by unsolicited vaginas.

So these are what I'm talking about, at the rear. I don't know what head that is, it has small round passages rather than small teardrop ones along the sides, but it seems to have all the holes drilled.

"I concluded that the GrpA holes were useful as far as assisting in getting some cooler coolant up under #1, #2, and #3 exhaust port structures in the head [#4 already has it]; and that the 2 added holes behind #4 bore would also assist in getting the flow up into the very rear of the head.

BUT, I had some reservations about adding those holes because of what I concluded about the flow through the head.
The flow is intended to go rearward in the block; then rise up into the head at #4 and then come forward to the thermostat housing. [that is the general desired flow path] The passages that let coolant up into the head at #1, #2, and #3 are there to mix in some cooler coolant to the already heated coolant that has gone all the way to #4 and is coming forward...to even out the temp of the coolant; to try to get and keep all four combustion chamber structures at the same temperature." Stealthftihttp://www.forums.turbobricks.com/sh...7&postcount=25

Have you thought about using an electric pump only to try and improve coolant flow before drilling into the head and having the interruption of coolant flow like some believe? You'd then remove the draw on the engine from the pump as well.